The payment authorisation does not check out

It concerns AP2, the payment authorisation. The Agent Payments Protocol. It proves a real person authorised the agent to spend, so you are not taking an agent's word for it.

Most agents fail at this point. The few that find a way round it spend more time and model calls doing so, and may give up before checkout.

Validate the mandate's structure and signature chain before acting on it.

Run the check that reported AP2_MANDATE_INVALID again after the change. The scan needs no account; an issue found during an AI shopping test needs that test run again.

$ npx @tragent/cli scan https://your-store.com

• Your payment-authorisation address does not answer
• No payment authorisation was presented
• You accept payment authorisation without checking it